兔肘关节尺侧副韧带急性损伤手术与非手术治疗后的生物力学比较

目的 比较兔急性肘关节尺侧副韧带损伤后手术修复与非手术治疗效果的差异.方法 选取新西兰兔81只,完全随机分为三组,27只暴露出右尺侧副韧带后,但不切断,作为正常对照组(A);27只为切断右肘尺侧副韧带后随即缝合韧带,称为韧带缝合组(B);27只切断尺侧副韧带后不缝合,称为韧带不缝合组(C).分别在术后3,6,12周三个阶段取材,进行生物力学检测.结果 术后12周,B组断裂时的位移为(6.06±0.48)mm,C组为(7.72±0,44)mm(P＜0.05),B组位移接近A组[(5.87±0.46)mm](P＞0.05);B组的最大载荷为(68.23±5.64)N,C组为(42.45±3.66)N(P＜0.05),B组接近A组[(72.86±2.99)N](P＞0.05);B组的轴向刚度为(11.33±1.52)N/mm,C组为(5.52±0.67)N/nan(P＜0.05),B组接近A组[(12.49±1.44)N/mm](P＞0.05);B组的功耗为(0.206±0.017)J,C组为(0.163±0.013)J(P＜0.05),B组接近A组[(0.213±0.010)J](P＞0.05).结论 肘关节尺侧副韧带急性损伤后手术治疗明显优于非手术治疗.     

自体半腱肌腱重建距跟骨间韧带动物模型

目的:利用自体半腱肌腱移植建立距跟骨间韧带重建的动物模型。方法:将72只新西兰白兔随机分为重建组、切断组和对照组。分别于4周、8周、16周、32周取材,对3个实验组术前术后体重变化,重建韧带的影像学、组织学和生物力学结果以及术后距下关节的活动范围进行评估。结果:术后8周以后实验动物体重变化出现差别,韧带切断组较重建组体重多增加0.32 kg(P=0.04);影像学、组织学和生物力学均支持移植韧带成活,生物力学研究发现韧带牵拉时出现2个张力屈服点;术后3组距下关节冠状面(P<0.05)和水平面(P<0.001)活动度差异有统计学意义。结论:利用自体半腱肌腱移植重建距跟骨间韧带可有效恢复距下关节的解剖和功能。移植韧带经过坏死、塑形改建、成熟的过程与骨道形成末端结构愈合。对于研究距下关节稳定性、韧带断裂后关节的继发性改变、韧带移植重建的转归提供了良好的动物模型材料。     

单纯后交叉韧带断裂继发关节内损伤的临床研究

自 1 973年至 2 0 0 2年间我所诊治单纯后交叉韧带断裂共 5 4例 ,其中进行了关节内探查的有 40例 ,急性伤 9例 (≤ 6周 ) ,慢性伤 3 1例 ( >6周 )。分别对这 40例病例的关节软骨损伤发生率、损伤部位和损伤程度及半月板损伤的发生率、损伤部位及损伤类型进行了统计学研究 ,同时对前、后交叉韧带断裂之间和运动员与非运动员之间的继发关节内损伤进行了统计学比较 ,对创伤机制也进行了相应的研究。结果显示 ,后交叉韧带断裂最常见创伤机制为胫前伤 ( 5 1 85 % )。非运动员中摩托车伤最多见 ( 2 3 5 3 % )。伤后慢性期软骨损伤发生率明显高于急性期 (P <0 0 5 )。前、后交叉韧带断裂后急性期与慢性期之间及运动员与非运动员之间软骨损伤发生率无明显差异。后交叉韧带断裂后软骨损伤最易发生于髌股关节 (P <0 0 1 ) ,其次为股骨内髁负重区 ,与前交叉韧带断裂更易发生于内、外髁相比 ,明显不同。非运动员软骨损伤程度要重于运动员 (P <0 0 5 )。后交叉韧带断裂后急慢性期半月板损伤发生率相近。慢性期外侧半月板损伤居多 (P <0 0 1 )。运动员更易发生半月板损伤 (P <0 0 1 )。后交叉韧带断裂后内外侧半月板损伤均少于前交叉韧带 ,慢性期尤甚 (P <0 0 0 1 )。后交叉韧带断裂后半月板损伤的部位以外侧     

犬下颌骨骨折内固定术后应力遮挡效应的实验研究

 目的 对下颌骨骨折内固定术后拆除小型接骨板前后应力遮挡效应进行动物实验研究,为下颌骨骨折愈合后内固定材料的远期处置提供理论依据。 方法 18只犬中3只犬即刻处死测定下颌骨骨密度和最大断裂力,该组设为正常组。其余15只犬人为造成双侧下颌骨骨折并行双侧小型接骨板固定（每只犬右侧为实验侧,左侧为对照侧）。固定2个月后,3只犬处死双侧取板测定骨密度和最大断裂力,该组设为0月组;其余12只犬右侧（实验侧）小型接骨板全部取出,取板后再经过1、2、3、6个月后各处死3只犬取左侧（对照侧）板,分别设为1、2、3、6个月组。比较左右两侧下颌骨在骨密度、最大断裂力上的异同。 结果 1、2、3、6个月组实验侧和对照侧骨密度值比0月组高（ P <0.05）,实验侧和对照侧比较各组之间差异无统计学意义。6个月组对照侧的骨密度值与正常组比较较低,差异有统计学意义（ P <0.05）。1、2、3、6个月组实验侧和对照侧与0月组比较最大断裂力值较高（ P <0.05）。实验侧和对照侧比较,各组间最大断裂力差异均无统计学意义; 6个月组对照侧与正常组比较最大断裂力值较低,差异有统计学意义（ P <0.05）。 结论 随着内固定时间的增加,在本实验中出现了应力遮挡效应。另外在内固定3个月时下颌骨实验侧和对照侧骨密度和最大断裂力值较高,说明内固定3个月时拆除接骨板可能最有利。     

肘关节后外侧旋转不稳定的解剖与生物力学研究

目的 研究肘关节外侧软组织对维持肘关节后外侧旋转稳定的作用。方法 通过解剖肘关节,观察外侧软组织的形态结构特点;将16侧上肢标本分为两组,通过生物力学试验,研究按顺序切断桡侧软组织结构时肘关节旋转度的变化。结果 肘关节伸肌起始于肱骨外髁的肌腱膜上,肌腱膜部分随肌肉走行成为肌间隔,部分止于尺骨鹰嘴外侧骨面;桡侧副韧止于尺骨冠突的部分为桡侧尺副韧带,其与桡骨环状韧带在尺度上的止点有2种类型。肘关节桡侧副韧带复合体对维持关节外侧稳定的作用约占50％,伸肌及伸肌腱膜的作用约占11％;在桡侧副韧带复合体中,桡侧副韧带（包括桡侧尺副韧带）起主要作用,桡骨环状韧带起协同作用。结论 肘关节后侧旋转不稳定除桡侧副韧带的损伤外,可能还有外侧伸肌及伸肌腱膜的损伤。     

持续被动活动对兔重建前交叉韧带生物力学特性的影响

目的:采用半腱肌腱重建兔前交叉韧带(ACL),探讨持续被动活动(CPM)对移植物生物力学特性的影响。方法:对30只8月龄雄性新西兰大白兔右侧后肢膝关节行自体双股半腱肌腱移植重建前交叉韧带手术。术后随机分为CPM组和非CPM组两组:CPM组术后第2天开始采用自制兔膝关节CPM器进行持续被动活动,共6周;非CPM组仅笼养。分别于术后第6、12、24周取材,每组每次取5只行生物力学观察。结果:与非CPM组相比,CPM组大部分标本两束融合成一体。从术后6周到24周,所有移植物的最大载荷、最大应力、弹性模量以及这些指标和其对照侧ACL的比值逐渐增加。在术后6、12、24周时,CPM组移植物最大载荷分别为22.72N、79.56N、122.20N,最大应力分别为4.58MPa、13.62MPa、21.79MPa;非CPM组移植物最大载荷分别为16.00N、70.68N、96.20N,最大应力分别为3.07MPa、11.58MPa、17.89MPa。3个时间点两组间上述指标差异均具有统计学意义(P<0.05)。结论:半腱肌腱重建兔前交叉韧带术后早期进行持续被动活动可明显提高移植物的生物力学性能。     

踝关节镜下清理术及小切口辅助外侧副韧带重建术后的康复研究

目的:研究踝关节清理术及外侧副韧带重建术后康复治疗计划。方法:将36例踝关节镜下外侧副韧带重建术后的患者随机分为康复治疗组和对照组,其中康复治疗组20例、对照组16例。两组患者均采用常规的非甾体类抗炎药物和短波、脉冲磁疗、半导体激光治疗。康复治疗组同时按踝关节镜下清理术及小切口辅助外侧副韧带重建术后康复治疗计划进行康复训练,采用改良McGuire踝关节评分系统(1988)评估其疗效。对两组患者分别于术后4、8、12、16和24周进行疗效观察和功能评定。结果:两组患者术后4周踝关节功能评分无显著性差异(P>0.05);术后8周,康复治疗组踝关节功能评分较对照组有所提高,但无显著性差异(P>0.05);术后12周、16周和24周康复治疗组踝关节功能评分与对照组相比有明显改善,具有显著性差异(P<0.05,或P<0.01)。结论:根据踝关节及其外侧副韧带损伤的特点和手术方式,设计科学、系统、安全、有效的踝关节镜下清理术及小切口辅助外侧副韧带重建术后的康复治疗计划,并据此对术后患者进行系统的康复训练,对踝关节功能的恢复有明显促进作用。     

自体半腱和股薄肌腱移植双束重建膝关节后外侧角

目的:观察采用自体半腱和股薄肌腱移植双束重建膝关节后外侧角韧带结构的近期临床效果。方法:对21例膝关节后外侧角韧带结构损伤患者(23个膝关节),采用自体半腱和股薄肌腱移植,双束重建膝关节后外侧角韧带结构。自体半腱肌腱移植物经胫骨骨道和腓骨骨道返折分别重建腘肌腱和腘腓韧带,于腘肌腱股骨外侧髁解剖止点处钻孔固定重建的腘肌腱和腘腓韧带;股薄肌腱移植物经腓骨骨道返折重建腓侧副韧带,于腓侧副韧带股骨外侧解剖止点处钻孔固定重建的腓侧副韧带。对于合并交叉韧带损伤者,同期行关节镜下韧带重建术。术后对患者膝关节内翻稳定性和外旋活动度进行至少1年(12~31个月,平均26.7个月)随访,通过Lysholm膝关节评分法评价膝关节术前、术后功能。结果:术后1年以上的回顾性随访中,膝关节完全伸直位无膝内翻不稳定者;屈膝30°位,无膝内翻不稳定者19例,膝内翻Ⅰ度不稳定伴硬性终止点者2例;俯卧位膝关节屈膝30°,所有患者小腿外旋活动均与对侧相同;Lysholm膝关节评分术前平均54.3分,术后平均89.2分。结论:自体半腱和股薄肌腱移植双束重建膝关节后外侧角韧带结构具有移植腱割取创伤小、移植材料理想、解剖等长重建及固定强度高的特点,近期疗效理想。     

板股韧带的MRI研究及临床意义

目的　明确板股韧带正常MRI表现 ,建立由它所致假撕裂与外侧半月板后角真撕裂的鉴别方法。资料与方法　采用 6 0侧正常膝进行矢状和冠状位MR扫描 ,观察板股韧带的MRI表现。结果　板股韧带显示率为88.3% (5 3侧 ) ,其中板股前韧带为 2 6 .7% (16侧 )、板股后韧带为 86 .7% (5 2侧 )和两条韧带同时存在为 2 3.3% (14侧 )。板股韧带在矢状像上表现为位于后交叉韧带前或后方的类圆形或短棒状低信号结构 ,而在冠状像上表现为自外侧半月板后角至股骨内侧髁外侧面的条带样低信号结构。在矢状像上 ,5 2 .8% (2 8/5 3)板股韧带与外侧半月板后角之间显示出一线样高信号 ,被称为假撕裂 ,易与外侧半月板后角撕裂混淆。但假撕裂仅有两种走行方向即后下斜行 (2 1/2 8)或垂直方向 (7/2 8)。结论　根据假撕裂位置、方向以及冠状像和连续矢状面的观察 ,可正确区分外侧半月板后角真假撕裂     

膝关节韧带损伤的MRI诊断价值

目的:探讨膝关节韧带损伤的MRI表现特点。方法:回顾性分析50例损伤的膝关节韧带的MRI表现。结果:本组50例87根韧带损伤,其中前交叉韧带15根(17.2%),后交叉韧带18根(26.7%),外侧副韧带15根(17.2%),内侧副韧带39根(44.8%)。50例中复合韧带损伤16例37根,其中前交叉+后交叉+外侧副韧带3例9根,前交叉+后交叉+内侧副韧带2例6根,前交叉+内侧副韧带3例6根,后交叉+内侧副韧带3例6根,后交叉+外侧副韧带3例6根,前交叉+外侧副韧带2例4根。单一韧带损伤34例50根,其中前交叉韧带5根,后交叉韧带7根,外侧副韧带7根,内侧副韧带31根。韧带完全横断撕裂7根,其中前交叉韧带1根,后交叉韧带2根,内侧副韧带3根,外侧副韧带1根。87根中部分纵行撕裂80根;7根完全断裂中3根交叉韧带MRI表现为韧带的连续性中断,断端回缩,局部或弥漫性肿胀,PDWI上呈中等信号,T2WI和脂肪抑制序列呈高信号;4根侧副韧带MRI表现为韧带连续性中断或韧带肿胀增粗,PDWI上呈中等信号,T2WI和脂肪抑制序列呈高信号。80根部分纵行撕裂MRI表现为韧带连续性完整,韧带增粗,PD-WI上呈中等信号,T2WI和脂肪抑制序列呈高信号。经手术关节镜检查21例33根,与MRI诊断相符31根,不符合2根,符合率为93.9%。54根经保守治疗后30~40天MRI复查见韧带原异常高信号而恢复至正常低信号,韧带形态类似正常,33根经关节镜下行韧带重建修复术,30~40天MR复查见原异常高信号而恢复至正常低信号,但局部成角或形态仍不规则。结论:MRI对软组织有极高的分辨率,不仅能较清楚显示膝关节韧带损伤,并能显示半月板损伤和骨挫伤,具有较高的实用价值。     

Anterior cruciate ligament allograft transplantation. Long-term function, histology, revascularization, and operative technique

In recent years much effort has been devoted to finding a satisfactory replacement for the injured ACL. None of the reconstruction techniques used in the past can be considered ideal because of their inability to duplicate the complex geometry, structure, and function of the ligament. Current advances in allograft transplantation and cryopreservation have led us to design and implement an experimental model for testing the feasibility of cryopreserved ACL allotransplantation. Groups of dogs were used to evaluate the effect of cryopreservation on ligament strength and to compare the relative performance of both autograft and allograft ACL transplants up to 18 months after implantation. The ligaments were examined mechanically, histologically, and microangiographically. The cryopreservation process and duration of storage had no effect on the biomechanical or structural properties of the ligament. The mechanical integrity of the allografts was similar to that of the autografts, with both achieving nearly 90% of control ligament strength by 36 weeks. Revascularization approached normal by 24 weeks in both autograft and allograft. No evidence of structural degradation or immunological reaction was seen. Based on these results, we believe that a cryopreserved ACL allograft can provide the ideal material for ACL reconstruction. We have outlined a surgical technique for harvesting and implanting this graft clinically.     

骨骼肌急性拉伤后牵张训练对其材料力学性能影响的实验研究

目的:探讨牵张训练对骨骼肌急性拉伤后恢复期材料力学性能影响的规律.方法:92只SD大鼠为实验对象,选取10只为空白对照组,其余82只在同等条件下对其小腿三头肌实施急性拉伤后,随机分为实验对照组、牵张组和跑动组.于不同恢复期取腓肠肌进行拉伸测试,获取试样的拉伸极限张力-时间曲线,计算其应力、应变及弹性模量.结果:(1)极限应力:伤后第10天,牵张组和跑动组小腿三头肌的极限应力明显高于实验对照组(P<0.05);伤后第17天,牵张组小腿三头肌的极限应力恢复值最高(PPT-EC<0.05).(2)极限应变:肌肉伤后第30天实验对照组小腿三头肌极限应变仅为正常肌肉的85.93%(P<0.01);伤后第10天牵张组肌肉极限应变为正常肌肉的98.19%,第17天则明显高于正常肌肉(P<0.01);跑动组伤后第10天也明显恢复(P<0.01).(3)杨氏模量:牵张对肌肉的模量的影响较自然修复及跑动训练均更明显.结论:急性拉伤肌肉抗拉性能基本恢复约需3周,应变恢复相对较慢.牵张对肌肉伤后的材料力学性能有积极的影响,但以影响应变性能和优化模量为主.肌肉急性拉伤后进行适量的跑动对肌肉的材料力学性能有积极作用,大强度跑动致重复性损伤的可能性加大.     

Allograft ligament transplantation. A morphological and biochemical evaluation of a medial collateral ligament complex in a rabbit model

Our purpose in this investigation was to describe and compare several morphological, histological, vascular, and biochemical healing processes of allograft and autograft bone-medial collateral ligament-bone complexes in a rabbit model. Forty-nine animals had their right medial collateral ligament complex replaced with a frozen allograft while 30 separate control animals each received a fresh autograft. Animals were sacrificed at 3, 6, 12, 24, or 48 weeks after transplantation for comparison of grafted with unoperated contralateral control complexes. Results demonstrate some recovery of both allografts and autografts over time. Allografts generally showed slower recovery than autografts with more persistent abnormalities in gross appearances, increased cellularity (corresponding to increased DNA content), and decreased collagen content. Allografts also showed aggressive remodeling of bone at insertions and they remained hypervascular throughout their substance as compared with contralateral controls. Autografts went through similar but less chronic increases in cellularity and DNA concentration with no changes in collagen content. While both types of grafts showed some signs of "healing" and some recovery of control ligament biology, results are also consistent with allograft encasement, infiltration, and at least partial replacement by host tissue. This was particularly true of insertions. Collectively, these results also demonstrate some differences between allografts and autografts in this extraarticular model. The causes, mechanisms, and longer-term consequences of these changes, including defining the qualities of these graft and host tissues, clearly requires further investigation.     

Variation in radiation-induced apoptosis in ataxia telangiectasia lymphoblastoid cell lines

Purpose : To investigate and compare the ability of Epstein-Barr virus-transformed lymphoblastoid cell lines (LCL) from healthy individuals (normals) and ataxia telangiectasia (A-T) patients to undergo apoptosis after exposure to ionizing radiation. Materials and methods : Four normal and eight A-T LCL were exposed to doses of up to 20 Gy ionizing radiation. Apoptosis induction was studied 24 h after irradiation using three different methods: measurement of caspase-3 activity, PARP-1 cleavage and estimation of the sub-G 1 cell fraction. Results : Of the eight A-T LCL tested, all harbouring truncating ATM mutations, five had a higher level of spontaneous apoptosis than the normal LCL as assessed by the sub-G 1 cell fraction. Four of the eight A-T LCLs showed a similar level of radiation-induced apoptosis after exposure to 5 Gy as the normal LCL. The other four A-T LCL showed a greater radiation-induced apoptotic response, as assessed by at least one of the three techniques. Conclusions : LCL from A-T patients can undergo ionizing radiation-induced apoptosis in spite of a defect in ATM-p53-dependent signalling pathways. However, the apoptotic response is characterized by a large degree of variability between the A-T cell lines, the causes of which remain to be established.     

膝关节韧带联合损伤的关节镜治疗后康复护理效果分析

目的探讨关节镜下膝关节前交叉韧带、后交叉韧带、内侧副韧带、外侧副韧带、后外侧结构联合损伤的康复护理效果。方法2003年10月—2005年11月,采用关节镜下重建交叉韧带,修复或重建侧副韧带和后外侧结构治疗急性膝联合韧带损伤12例。术后早期等长肌力练习、早期完全负重、早期本体感觉练习、早期被动练习。出院后随诊并功能评分。结果12例均获得随访,随访时间6~24个月,平均14个月。Lysholm评分:优2例,良8例,可2例。关节稳定性良好,有2例腘绳肌腱重建者抽屉试验Ⅰ度阳性。膝关节屈曲超过120°者9例,90~120°者3例。结论膝关节联合韧带损伤关节镜手术治疗配合正确的康复护理可取得良好效果。     

Variation in radiation-induced apoptosis in ataxia telangiectasia lymphoblastoid cell lines

PURPOSE: To investigate and compare the ability of Epstein-Barr virus-transformed lymphoblastoid cell lines (LCL) from healthy individuals (normals) and ataxia telangiectasia (A-T) patients to undergo apoptosis after exposure to ionizing radiation. MATERIALS AND METHODS: Four normal and eight A-T LCL were exposed to doses of up to 20 Gy ionizing radiation. Apoptosis induction was studied 24 h after irradiation using three different methods: measurement of caspase-3 activity, PARP-1 cleavage and estimation of the sub-G(1) cell fraction. RESULTS: Of the eight A-T LCL tested, all harbouring truncating ATM mutations, five had a higher level of spontaneous apoptosis than the normal LCL as assessed by the sub-G(1) cell fraction. Four of the eight A-T LCLs showed a similar level of radiation-induced apoptosis after exposure to 5 Gy as the normal LCL. The other four A-T LCL showed a greater radiation-induced apoptotic response, as assessed by at least one of the three techniques. CONCLUSIONS: LCL from A-T patients can undergo ionizing radiation-induced apoptosis in spite of a defect in ATM-p53-dependent signalling pathways. However, the apoptotic response is characterized by a large degree of variability between the A-T cell lines, the causes of which remain to be established.     

不同运动方式对骨性关节炎关节功能恢复的防治效果

目的了解不同运动方式对骨性关节炎(OA)关节功能改善的影响,以评价运动对OA防治效果。方法采用新西兰白兔左后膝长腿石膏管型伸直位固定的方法建立OA动物模型,依运动方式不同按随机分组原则进行分组,观察关节X线变化、活动度改善和关节周围韧带生物力学特性改变。结果X线表现示关节适宜运动有助于OA病情逆转,运动对恢复OA的关节活动度具有重要作用,可显著增强关节周围韧带抗张强度的恢复。结论运动可明显改善OA关节功能,延缓病情发展,主动加被动活动是最佳运动方式。     

Effects of administration of exogenous growth factors on biomechanical properties of the elongation-type anterior cruciate ligament injury with partial laceration

BACKGROUND: No studies have been conducted to clarify the in vivo effect of growth factor application on healing in the injured anterior cruciate ligament. HYPOTHESIS: Administration of exogenous growth factors significantly increases the structural properties of the injured anterior cruciate ligament. STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-six rabbits were randomly divided into 4 groups of 9 animals each after an overstretched injury was made in the right anterior cruciate ligament. In group 1, no treatment was applied around the injured anterior cruciate ligament. In group 2, 0.2 mL fibrin sealant was applied around it. In group 3, 4 ng transforming growth factor-beta1 mixed with 0.2 mL fibrin sealant was applied. In group 4, 20 microg platelet-derived growth factor-BB mixed with 0.2 mL fibrin sealant was applied. Each rabbit was sacrificed at 12 weeks after the surgery. In addition, 9 knees randomly harvested from all the left knees were used to obtain normal control data. The femur-anterior cruciate ligament-tibia complex specimens were biomechanically and histologically evaluated. RESULTS: Concerning the maximum load and the stiffness, group 3 was significantly greater than groups 1 and 2, whereas there were no significant differences among groups 1, 2, and 4. Groups 1, 2, 3, and 4 were significantly lower than the control group. CONCLUSIONS: The application of 4 ng transforming growth factor-beta1 significantly enhances healing in the injured anterior cruciate ligament. CLINICAL RELEVANCE: Administration of certain growth factors is of value to be studied as one of the future therapeutic options for the overstretched anterior cruciate ligament injury.     

Low-intensity pulsed ultrasound accelerates and a nonsteroidal anti-inflammatory drug delays knee ligament healing

BACKGROUND: Low-intensity pulsed ultrasound and nonsteroidal anti-inflammatory drugs are used to treat ligament injuries; however, their individual and combined effects are not established. HYPOTHESES: Low-intensity pulsed ultrasound accelerates ligament healing, a nonsteroidal anti-inflammatory drug delays healing, and the nonsteroidal anti-inflammatory drug inhibits the beneficial effect of low-intensity pulsed ultrasound. STUDY DESIGN: Controlled laboratory study. METHODS: Sixty adult rats underwent bilateral transection of their knee medial collateral ligaments. Animals were divided into 2 drug groups and treated 5 d/wk with celecoxib (5 mg/kg) mixed in a vehicle solution (NSAID group) or vehicle alone (VEH group). One to 3 hours after drug administration, all animals were treated with unilateral active low-intensity pulsed ultrasound and contralateral inactive low-intensity pulsed ultrasound. Equal numbers of animals from each drug group were mechanically tested at 2 weeks (n = 14/group), 4 weeks (n = 8/group), and 12 weeks (n = 8/group) after injury. RESULTS: Ultrasound and drug intervention did not interact to influence ligament mechanical properties at any time point. After 2 weeks of intervention, ligaments treated with active low-intensity pulsed ultrasound were 34.2% stronger, 27.0% stiffer, and could absorb 54.4% more energy before failure than could ligaments treated with inactive low-intensity pulsed ultrasound, whereas ligaments from the NSAID group could absorb 33.3% less energy than could ligaments from the VEH group. There were no ultrasound or drug effects after 4 and 12 weeks of intervention. CONCLUSIONS: Low-intensity pulsed ultrasound accelerated but did not improve ligament healing, whereas the nonsteroidal anti-inflammatory drug delayed but did not impair healing. When used in combination, the beneficial low-intensity pulsed ultrasound effect was cancelled by the detrimental nonsteroidal anti-inflammatory drug effect. CLINICAL RELEVANCE: Low-intensity pulsed ultrasound after ligament injury may facilitate earlier return to activity, whereas non-steroidal anti-inflammatory drugs may elevate early reinjury risk.     

Analysis of proprioception in the posterior cruciate ligament-deficient knee

The purpose of this study was to demonstrate loss of proprioception with posterior cruciate ligament (PCL) deficiency. Eight patients with isolated PCL-deficient knees were examined to determine whether or not the proprioceptive function of the knee joint was affected or impaired by the previous tear of the PCL. The patients were examined for perception of passive movement of the knee joint using a motorized apparatus which extended or flexed the patient's knee at a rate of 0.5 deg/s in a randomized sequence. The patient's normal contralateral knee was used as a control. This study demonstrated a significant difference in proprioception in the patient's PCL-deficient knee. All eight PCL-deficient knees clearly demonstrated slower perception of passive movement when compared with the contralateral normal knee. Injuries to the PCL resulting in impaired proprioception may play a role in knee instability, further damage and ultimately the degenerative changes frequently seen in the longterm follow-up of PCL-deficient knees.